Are there certain years or decades when homes started to become more insulated and energy efficient?

Question

I'm starting to house shop, I live in the frigid Midwest. I remember we lived in an early 1900s house in college and our winter energy bill was crazy high like $500, im guessing it depends on region and many other factors but is there a rough decade where houses started to become more energy efficient or was it more of a gradual thing?

Answer 1

not so simple. early in the past century, houses were routinely built without insulation in the attic [in between the floor joists in the attic]. by the after war period [about 1950] they were routinely built with only four inches [100mm] insulation there. And more serious insulation [150mm or six inches] didn't become common until the 1980s or 1990s, usually in higher end housing.



BUT, much depends on what a prior owner did to improve that. If the house was a rent house, landlord likely did nothing at all [because the energy bill, whether gas or electric, was paid by tenant]. An owner, however, may well have added further insulation ... my house, for example has ten inches [250mm] total -- added by prior owner.



What you do when shopping is a) ask for the prior year's energy bills [or written permission to energy suppliers for them to show you the bills which you take to supplier's office] AND b) literally go up in the attic and inspect the insulation. [You can NOT rely on a home inspection service to do this -- having little insulation isn't a defect and they won't mention it.]



Note that in the walls insulation was quite similar. And in a cold February wind, four inches in the walls may not be sufficient, depending on your climate. [Example: my daughter's house in Vermont had two more inches added to the walls by her husband over a period of a decade or so. He literally removed the exterior siding, shimmed out the upright studs using 2x2 stock, and then fitted 2 inch thick insulation board between the studs before restoring the siding. (great value add summer project which he didn't do until he already had 12 to 16 inches in the attic.)]

Answer 2

As energy increased in price, so did the concept of insulating homes.

Answer 3

yes the 1980's 

Answer 4

Houses built in the early 60s were insulated, but not very well yet. But then, utility bills weren't that high then, either. 





Late 1960's, early 1970's was when we began to explore energy efficiency; better windows, more types of insulation available, attic spaces ventilated, etc. Heating bills started to go up then and people wanted ways to offset the extra costs. It wasn't that gradual--it was more of a 'trend' that started to really take off as people discovered it. 

Answer 5

Energy efficiency started to become an issue after the OPEC oil embargo in 1973.  Houses built after that year have become progressively more energy efficient with every update to the Building Codes.

https://en.wikipedia.org/wiki/1973_oil_crisis

Answer 6

Yes. EVERY decade they typical new home was more thermally efficient than the prior decade.

Answer 7

After WWII a lot of the new houses had insulation in the ceiling but not necessarily in the walls. It varied a bit based on geographic location. The big change came in the 60's and 70's as the cost of energy started to rise. After the energy crisis of the 70's the degree of insulation started to increase and older non insulated homes started getting retrofitted for insulation. Even then the degree of insulation varied some based on location. 

Answer 8

70's they did some insulation before then but it's hit or miss.  

Answer 9

My best guess, and it's a guess because a little googling didn't produce a definitive answer, is that insulation began to be widely used in the 1970s after energy prices shot up. That's when people really began to get serious about it.



I built a house in 1993. We debated whether or not to use 2x4 exterior framing, or 2x6 as some people were starting to do.  2x6 allows 2 more inches of insulation. There was no question about whether or not to use double glazed windows, By then, the building code required them. Before codes require things, people are free to build them if they want to, but they don't have to. And people can retrofit some things like double glazing to an older house, though I'm not sure how successful it is to insulate walls later.



But I'm in Canada where it looks like we had a national building code before the US did. The US seems to have had regional codes until 2000. And, of course, different local governments can require more than a general national code calls for.



In most places, a utility company can tell you what the bill was for the previous year if you give them the address. In the case of electricity you can't separate out how much was for heat, but gas and oil are clearly going to be almost entirely, if not entirely, for heat.

Answer 10

I don't think the even insulated houses in 1900.  (But I was just a little boy then so I don't remember.)



Energy started getting expensive in the early 70s.  I remember at the time that there was a lot of new research into insulation products and techniques.  That was when we all learned about R values.



But lots of older buildings were retrofitted.  So you can't go just by age.

Answer 11

There is, but I just wanted to point out that it's more important to find out what has been done to a specific house since it was built as insulation can be retrofitted.  When looking at houses find out what's been done to the house and what is possible to do to the house (and how much that would cost).  Depending on how it was built that early 1900s house could be made very snug.

Answer 12

It started with the first oil embargo when Jimmy Carter was President. 1976. But, it took years to develop standards, materials, construction techniques and general practice to put good quality efficiency in place. Things were retrofitted, but that is not equivalent to a purpose built insulated home. So, my guess is that you have to get to about 1995 to get to housing that will have some decent insulating standards and materials. What you need to do is get a list of the energy efficiency standards and then check what you are buying to those standards before you buy. For example, there is no reason to build an exterior wall out of 2x4 and lower the R value and save a couple hundred dollars for wood studs. Compared to a 2x6 wall. The difference is one month heating bill. Likewise, attic insulation should be at least 24-30 inches in any climate, and requires a higher attic and landings and increase the insulation of A/C ductwork,  which does add cost.  Attic temperature is hot everywhere. Like wise, attic ventilation is most important. Continuous free flow of air from the soffit and out the ridge row vent. Find a well built house like that.

Answer 13

Yes, after the energy crisis of the 1970s laws were passed to make homes more energy-efficient. Since then the laws have become more stringent.  Many older homes have had redone exteriors and with that work have added insulation sheeting.